JPH06156416A - Stretch packaging device - Google Patents

Abstract

PURPOSE:To provide a stretch packaging device which is equipped with a mechanism to grip right and left both side edges of a film which is pulled out to a packaging section. CONSTITUTION:Both side edges 2c of a film 2 which is pulled out to a specified location of a packaging section B are gripped by a clamp mechanism F, and the film is stretched by moving the clamp mechanism F in the separating directions to each other, and an article to be packaged 1 is pushed up from the bottom of the film to cover the upper surface of the article to be packaged by the film, and both side edges of the film are folded to the bottom part side of the article to be packaged by a folding plate 28, for the stretch packaging device. Right and left movable clamp plates 20 which are separatable to the lower surface of the folding plate 28 which is constituted to be movable, and are synchronizable to the moving motion of the folding plate 28 are arranged under or in the vicinity of the right and left folding plates 28. By this method, the right and left both side edges 2c of the film 2 which is pulled out to the specified location of the packaging section B can be gripped by pressing the movable clamp plates 20 to lower surfaces of the right and left folding plates 28 and cooperating together with the right and left folding plate 28, and the film 2 can be stretched by a specified quantity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stretch wrapping apparatus, and more specifically, it holds both left and right side edges of a film drawn to a predetermined position of a wrapping section by left and right clamp mechanisms and separates the left and right clamp mechanisms from each other. The film to be stretched (pre-stretched) by moving in the direction, and the object to be packaged is pushed up from the bottom of the stretched film toward the film to cover the upper surface of the film with the film, and then the left and right sides of the film. TECHNICAL FIELD The present invention relates to a stretch wrapping device that folds both side edges to the bottom side of an article to be wrapped by left and right folding plates, and particularly to an improvement of a left and right clamp mechanism that holds both left and right side edges of a film drawn to a predetermined position of a wrapping portion.

[0002]

2. Description of the Related Art Conventionally, as this type of stretch wrapping device, for example, a device disclosed in Japanese Patent Laid-Open No. 56-64908 is known. The left and right clamp mechanism for gripping the widthwise both side edges of the film drawn out to the predetermined position of the packaging part of such a conventional device swings by pivoting a pair of left and right swing arms on the left and right sides below the packaging part. The left and right swing arms are provided with a fixed clamp piece at the upper end of the left and right swing arms and both movable clamp pieces that are opened and closed by a cylinder with respect to the fixed clamp pieces. The link mechanism is operated by a link rod connected to the drive unit side, and the upper ends of the left and right swing arms are swung from the outer standby position toward the inner sides approaching each other, that is, the predetermined packaging part. By swinging the left and right side edges of the film pulled out to the position, the left and right side edges are closed by the cylinder of the lower moving clamp piece with respect to the fixed clamp piece at the upper end of the left and right swing arm. More gripping, had to as to stretch the film by swinging outwardly in a width direction apart from each other the upper end of the left and right swing arms again (prestretch) in this state. Therefore, since the left and right clamp mechanism of the conventional device has a large number of parts and has a complicated structure, its assembly is troublesome and an installation space must be taken up, resulting in an increase in size of the device. Also, when the pair of left and right swing arms are swung inwardly toward each other or away from each other with their pivotally attached parts as fulcrums, the upper end is fixed, the movable clamp piece is fixed especially at the upper side. In order to prevent the clamp pieces from interfering with the left and right folding plates, the left and right folding plates must be placed in the packaging section with a space (height) to prevent interference between them. Since the pulled-out film and the left and right folding plates are separated from each other at the above-mentioned interval, it is necessary to increase the amount of upward push-up movement toward the film of the packaged object as much as it is separated. Since the amount of push-up movement after the top comes into contact with the film becomes large, it is necessary to release the grasped state of the left and right edges of the film at the same time as the folding operation of the left and right folding plates starts, and as a result, the film stretches. Will soon loosen It is difficult to carry out the wrinkles without beautiful packaging on the surface Te. Especially in recent years when environmental problems caused by non-burnable dust have been aroused, it is required to wrap the items to be packaged directly with a film without using trays. This is especially difficult with the packaging form.
Further, there are various problems such that the film and the left and right folding plates are separated by a height and the packaging position is increased.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above conventional circumstances, and the structure is simplified by reducing the number of parts, and moreover, the film drawn out to the packaging portion and the left and right folding plates. An object of the present invention is to provide a stretch wrapping device provided with a left and right clamp mechanism that makes it possible to hold both the left and right edges of the film in a state where the distance between the film and the film is not high.

[0004]

The technical means taken by the present invention to achieve the above-mentioned object is to grasp the left and right side edges of the film pulled out to a predetermined position of the wrapping portion by the left and right clamp mechanisms, and The clamp mechanism is moved in a direction away from each other to stretch the film, and the object to be packaged is pushed up from below the stretched film toward the film to cover the upper surface of the packaged object with the film, and then the film. In a stretch wrapping device that folds the left and right side edges of the left and right fold plates to the bottom side of the article to be wrapped by the left and right fold plates, the left and right fold plates are configured to be movable in a direction of separating from or approaching each other. The left and right folding plates are attached to the left and right folding clamp plates, which are movable left and right and can be synchronized with the movement of the folding plate in the direction of separation or approaching. Or characterized in that disposed in the vicinity thereof. Further, the left and right movable clamp plates are characterized in that they are held in pressure contact with the lower surfaces of the left and right folding plates to grip the left and right side edges of the film. Further, the left and right movable clamp plates are synchronized with the moving direction in which the left and right folding plates move toward or away from each other in a state of being pressed against the lower surfaces of the left and right folding plates, and when the left and right folding plates move or move in the approaching direction. It is characterized in that it is released from the left and right folding plates in the process and returns to the initial standby position.

[0005]

According to the above-mentioned technical means of the present invention, the movable clamp plates of the left and right clamp mechanisms are pressed against the lower surfaces of the left and right folding plates when the film is pulled out to the predetermined position of the packaging section. When the left and right edges of the film are gripped in cooperation with the left and right folding plates, and when the left and right folding plates move in the direction of separating from each other, the left and right movable clamp plates also move in synchronization with the left and right folding plates in the direction of separating. Then, the film is stretched (pre-stretched) by a predetermined amount in the width direction.
In addition, the movable clamp plate of the left and right clamp mechanism moves in a direction in which the left and right folding plates approach each other, that is, when the left and right edges of the film are moved in the direction in which they are folded to the bottom side of the packaged part, at the same time or in the movement process, The film is released from the folding plate to release the grasped state of the left and right edges of the film, and returns to the initial standby position.

[0006]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a side view showing the entire stretch wrapping apparatus of the present embodiment. A carrying-in section A for placing a product) is arranged on the front side of the apparatus machine frame 3, while a film 2 for wrapping the article 1 is horizontally pulled out and stretched in a stretched state.
Is disposed on the upper surface of the apparatus machine frame 3, and the film 2 is pulled out from the film supply mechanism J by a predetermined length at a position in the front and rear direction of the film withdrawing direction X of the wrapping part B, and the pulled-out film 2 is provided in the predetermined part of the wrapping part B. The film pulling-out machine C and the rear clamp mechanism D which are moved to the position, and the front and rear folding mechanism E for folding the front and rear edges 2a and 2b of the film 2 to the bottom side of the product 1.
And the width direction both side edges 2c of the film 2 transferred to a predetermined position are gripped on both sides of the packaging part B which intersects with the drawing direction X at the same time.
The left and right clamp mechanisms F for extending the predetermined width in the width direction and the left and right folding mechanism G for folding the left and right side edges 2c of the film 2 to the bottom side of the product 1 are respectively arranged, and the product 1 received from the carry-in part A is The transport table H for transporting to the wrapping section B is supported by the drive mechanism I and is movably arranged in the machine frame 3 in the horizontal and vertical directions, and the film withdrawing mechanism C wraps the film 2 of a predetermined length. The film 2 is pulled out to the part B and is transferred to a predetermined position of the packaging part B in cooperation with the rear clamp mechanism D, and the left and right side edges 2c of the film 2 are left and right folding mechanism G and left and right clamp mechanism F at the position. The film 2 is stretched in the width direction by a predetermined amount by being gripped and stretched in a collaborative operation with the film, and the transport table H is moved from below the film 2 to a horizontal operation unit I- of the drive mechanism I, which will be described later. 1 After the push-up increases the product 1 received from an upper face carrying unit A by the horizontal movement and vertical movement by the vertical operation unit I-2, 2 of the front and rear edges 2a of the film,
The product 1 is packaged by folding the 2b and the left and right side edges 2c on the bottom side of the product 1 by the front and rear folding mechanism E and the left and right folding mechanism G.

The carrying-in section A is formed by forming a plurality of loading rods 4 into a flat comb-like shape with the other end opened so that one ends of the mounting rods 4 are connected and supported at appropriate intervals. Receiver
By passing 37 between the loading rods 4, the commodity 1 placed on the loading rods 4 can be received. The carrying-in section A is fixedly supported on the supporting rods 6 on both sides projecting from the measuring instrument 5 with a built-in load cell, which is disposed at the central portion in the height direction on the front surface of the machine frame 3, and is above the measuring instrument 5. After being arranged (see FIG. 2), the weight of the commodity 1 placed on the placing rod 4 is detected, and the label printer (not shown) prints the weight data and the price calculated based on the weight data. The label will be printed. The product 1 may be placed on the carry-in section A either manually by an operator or automatically by a supply conveyor or the like.

The packaging section B has a film drawing mechanism C for grasping the front edge 2a of the film 2 and pulling the film 2 from the film supply mechanism J at a predetermined length. A rear clamp mechanism D, which is horizontally movably arranged in the front-rear direction above the side, and which holds the trailing edge 2b of the film 2 pulled out to the upper part inside the machine frame 3, faces the film drawing mechanism C. 3 A left and right clamp mechanism F, which is arranged on the rear surface side so as to be horizontally movable in the front-rear direction (see FIGS. 1 and 2), and which holds both left and right edges 2c of the film 2 in the drawing direction X in which the film 2 is drawn out. They are arranged on both sides of the machine frame 3 which intersects (orthogonally) with each other (see FIG. 3), and the four peripheral edges of the film 2 pulled out from the film supply mechanism J are held by the respective mechanisms C, D and F. Pre-stretch the film 2 by a predetermined amount It is configured so as to be held in a tightening state.

The film pull-out mechanism C is formed in a plane comb-like shape with a length extending between both sides of the machine frame 3, one of which is fixed and the other is connected to the fixed side by a gripping cylinder (not shown). Both side guide shafts 8 in which both side ends of the film grasping portion 7 which performs an operation of grasping or releasing the front edge 2a of the film 2 by tilting freely so as to be detached are attached to both sides of the machine frame 3 in a crosswise direction. The slide bush 9 is connected and supported through a connecting tool 10 so as to be movable in the film drawing direction X, and one end side of the slide bush 9 is wound around the outer surface of one side of the machine frame 3 in the front-rear direction. Is connected to a timing belt 12 that rotates in the front-rear direction by a motor 11 and is arranged on the rear side of the machine frame 3 for holding the front edge (front edge) 2a of the film 2 fed from the film supply mechanism J. Presents a flat comb edge It can be moved to an appropriate position by the motor 11 within a range extending from the film leading end holding portion K to the front side of the apparatus frame 3 in the film drawing direction X. That is, the motor 11 carries out the pulling out length of the film 2 according to the size of the product 1 and the movement of the pulled out film 2 to a predetermined position of the packaging section B by a cooperative operation synchronized with the rear clamp mechanism D. It is configured to be On the other hand, the rear clamp mechanism D is formed to have a length that extends between both sides of the apparatus frame 3 like the film pull-out mechanism C, and the movable side can freely move toward and away from the fixed side by a gripping cylinder (not shown). Tilt to film 2
Both side ends of the film gripping portion 13 for gripping or releasing the trailing edge 2b are connected to and supported by the slide bushes 14 of the above-mentioned both-side guide shafts 8 via the connecting members 15, and one end side of the film holding portion 13 is used as a device machine. A motor 16 wound around the outer surface of the other side of the frame 3 in the front-rear direction is connected to a timing belt 17 that rotates in the front-rear direction, and the motor 16 synchronizes with its own movement and the film gripping portion 7 of the film drawing mechanism C. It is configured so that it can move to an appropriate position in the film drawing direction X by the above-mentioned cooperative operation.

The left and right clamp mechanism F is lifted up and down while being connected to and supported by the upper ends of the rods of the air cylinders 18 which are positioned substantially below the left and right folding plates 28, which will be described later, of the left and right folding mechanism G standing by in an open state. A movable clamp plate 20 formed in a frame 19 having a substantially L-shaped cross section is attached and supported by a guide pin 22 on which a spring 21 is wound so as to be movable in the folding and returning directions of the left and right folding plates 28. The cylinder 20 is lifted up and brought into pressure contact with the lower surfaces of the left and right folding plates 28 so that the left and right edges 2C of the film 2 can be gripped in cooperation with the left and right folding plates 28. That is, the left and right clamp mechanism F uses the left and right folding plates 28 as left and right fixed clamp plates (see FIG. 13B), and the movable clamp plate 20 is synchronized with the movement of the left and right folding plates 28 in the direction of separation. The film 2 which is moved in the separating direction and gripped is stretched in the width direction by a predetermined amount in cooperation with the left and right folding plates 28, and the product 1 is raised toward the same film 2 by the carrier table H. By detecting the top of the product 1 by a sensor L, which will be described later, arranged below the packaging part B in the upward process of being pushed up,
The movable clamp plate 20 is moved in the approaching direction in synchronization with the movement of the left and right folding plates 28 moving in the approaching direction to appropriately reduce the extension amount in the width direction of the film 2, that is, to loosen the pre-stretching amount. (Figs. 14 to 14)
See 15).

The front and rear folding mechanism E has a flat rectangular folding plate 23 formed in a length extending in the width direction of the machine frame 3 and is horizontally arranged in the front and rear direction on the film drawing mechanism C side and the rear clamp mechanism D side, respectively. Both ends of the chain 25 are movably arranged, and both ends thereof are fixedly connected by connecting arms 26 to the chains 25 on both sides which are tuned and rotated by the motors 24 which are wound around the both sides of the machine frame 3 in the front-rear direction. The leading edge and the trailing edge of the film 2 are folded at the bottom side of the product 1 at the same time by bringing them closer to each other at the moving speed.
A heater 27 for heat sealing is embedded and attached to either one of the front and rear folding plates 23, in the illustrated example, the folding edge of the front folding plate 23 (see FIGS. 3 and 13A).

On the other hand, in the left and right folding mechanism G, a strip-shaped folding plate 28 formed to have a length extending between the front and rear folding plates 23 standing by in a fully opened state is positioned on the front and rear folding plates 24. In this state, the left and right sides of the machine frame 3 are horizontally movably arranged, and the front and rear ends thereof are connected to the chain 25
Is supported and connected by a guide bush 31 to a rotating shaft 30 which is installed before and after being wound and held by a sprocket 29, and the rear ends of the left and right folding plates 28 are connected to the rear clamp mechanism D.
One end of each chain 32 is fixedly connected to the rear chain 32 wound around the side by a connecting arm 33, and the left and right side edges of the film 2 are made closer to each other at a moving speed synchronized by the motor 34. The product 1 is folded at the bottom side at the same time. That is, the movable clamp plate 20 of the left and right clamp mechanism F moves in the direction in which the movable clamp plates 20 of the left and right clamp mechanisms F move away from and approach each other by the drive of the motor 34 while being pressed against the lower surface of the folding plate 28 of the left and right folding mechanism G. It moves in synchronism (see Fig. 14 (a) (b) and Fig. 15).

The carrier table H receives the product 1 placed on the carry-in section A and weighed from the carry-in section A and conveys it to the lower side of the packaging section B and from the lower side to the packaging section B. It serves to push up and supply the film 2 which is pulled out and stretched and is on standby, and the standing portions 35 are provided at intervals so as to pass between the respective mounting rods 4 which are arranged in a comb-blade shape and which constitute the carry-in portion A. A receiving portion 37 for receiving the product 1 is fixedly disposed on each standing portion 35 of the formed head base 36 (see FIG. 4), and the driving mechanism I is supported via a supporting member 38 to drive the driving mechanism. It is arranged in the machine frame 3 by the movement of I so as to be movable in the horizontal and vertical directions.

The drive mechanism I is installed at the bottom of the machine frame 3 to move the carrier table H from the carry-in section A to the packaging section B. The carrier table H supported by the support member 38 is carried in. A horizontal operation part I-1 for horizontally moving between the section A and the packaging section B, and a vertical operation section I for vertically moving the carrying table H at each of the loading section A and the packaging section B. -2
Consists of. The support member 38 includes guide struts 39 on both sides of which the lower ends are fixedly attached to the bottoms of both sides of the machine frame 3, and both side guide struts 39 are supported between the both side guide struts 39 so as to be slidably movable up and down. 3. A vertical moving frame 40, which is horizontally arranged in 3 and is formed into a rectangular frame shape, and a guide groove 41 provided on the inner surface of both side frames of the vertical moving frame 40. A front and rear moving plate 42 is provided in the moving frame 40 so as to be slidably movable in the front and rear direction. The supporting leg 43 is formed in the front side of the upper surface of the front and rear moving plate 42 and has an L-shaped side surface. Even if the head base 36 of the carrier H is fixedly supported and the supporting rod 43 does not make the length of the support rod 6 too long, the carrier H
Is placed under the carry-in section A. (See Figure 1).

The horizontal operation unit I-1 is a reduction box 44 in which a gear mechanism, a so-called reduction mechanism, is built in the bottom of the machine frame 3.
A cam A47 attached to a cam shaft 46 that is connected to a main motor 45 installed via a cam, and the cam A47 is connected to the cam A47 to swing the front end side, that is, the swing end up and down with the rear end shaft support 48 as a fulcrum. A swinging arm A49 for moving and a swinging end of the swinging arm A49 are mounted by disposing the swinging arm A49, which has a substantially L-shaped side surface and a corner portion of the swinging arm 50, which is installed on the bottom of the machine frame 3. A starter arm 52 axially connected to the end of the short side via a connecting elongated hole formed over substantially the entire length and fixedly hung from the lower surface of the front and rear moving plate 42 of the support member 38. A vertical arm having a long side end portion of the starting arm 52 slidably slidably fitted and connected to the start arm 52.
A cam A composed of 54 and rotated by the main motor 45.
By the vertical swing motion of the swing arm A49 along the cam floor of 47, a longitudinal movement is caused on the long side of the starting arm 52 with the swing shaft 50 as a fulcrum to move the carrier H through the forward / backward moving plate 42. And move it from the carry-in section A to the lower side of the packaging section B (see FIG.
6) to the lower part of the carry-in part A from the lower part of the wrapping part B.

On the other hand, the vertical motion part I-2 is connected to the cam B55 attached to the cam shaft 46 and the cam B55, and the cam B55 is connected to the front end side or swing end with the rear end shaft support part 56 as a fulcrum. It comprises a swing arm B57 which swings up and down, and a connecting arm B58 which is mounted by pivotally connecting the ends of the swing arm B57 and the vertical moving frame 40 of the support member 38. By the vertical swing motion of the swing arm B57 swing end along the cam floor of the cam B55 which is rotated by the main motor 45, the transport base H is moved to the loading section A and the packaging section B via the vertical moving frame 40 respectively. It is configured to move up and down in. That is, in the loading section A, the state of FIG. 1 rises to the state of FIG. 5, and in the packaging section B, the state of the solid line of FIG. 6 rises to the state of the chain double-dashed line of FIG. It is configured so as to descend from the state of the chain line to the state of the solid line in FIG. In the figure, reference numeral 59 denotes a spring stretched over the apparatus frame 3 from the middle of the swing arm B57 in the longitudinal direction. The spring 59 suspends the swing arm B57 and moves the carrier table H upward. It sometimes works to reduce the load on the main motor 45.

The sensor L is such that the product 1 is pulled out to a predetermined position of the packaging portion B and is lifted and pushed up by the carrier table H toward the film 2 which is waiting to be stretched. It is a reflection type photoelectric sensor that detects when light is blocked, and is arranged at one corner on a diagonal line at a lower predetermined height position of the packaging section B, and is arranged at the other corner opposite to the diagonal side. The top of the product 1 is made to constantly irradiate light toward the reflection plate N, and when the light is not reflected by the reflection plate 1N, that is, when the light is blocked by the top of the product 1, it is operated and lifted up by the carrier table H. Detects that a predetermined position has been reached on the lower side of the film 2 of the packaging section B, and a detection signal is output,
The control means (not shown) outputs a signal to the motor 34 to start an operation of moving the movable clamp plates 20 of the left and right clamp mechanism F in a direction in which they approach each other.

Next, a packaging method using the packaging apparatus configured as described above will be described with reference to FIGS. 5 to 20. The product 1 is placed on the carry-in section A and the operation switch of the apparatus is turned on. Then, after the weighing by the weighing device 5 is completed, the operation is started, and first, the carrier table H waiting under the carry-in section A is lifted by the vertical operation section I-2 to move from the carry-in section A. At the same time when the product 1 is received (state of FIG. 5), the carrier table H is moved to the lower part of the packaging part B by the horizontal operation part I-1 while maintaining its height, and the product 1 is carried to the lower part. (State of FIG. 6). At this time, the film withdrawing mechanism C (in the state of FIG. 7) that holds the front edge 2a of the film 2 starts the film withdrawing operation at substantially the same timing, and the film with a predetermined length according to the size of the product 1 When the film 2 is pulled out to the wrapping part B and the film 2 is pulled out (state of FIG. 8), the rear clamp mechanism D moves from the standby position above and below the film front end holding part K to the rear edge of the film 2.
Hold 2b (state from FIG. 8 to state in FIG. 10). afterwards,
The film 2 is separated by the film cutting mechanism 0 between the film front end holding portion K and the rear clamp mechanism D (FIG. 11).
State), the film withdrawing device C and the rear clamp mechanism D are moved at the same timing and at the same speed at a predetermined timing after the film 2 is separated, and the packaging part B is moved.
12 is centered to a predetermined position (at the state of FIG. 12), and at the same time, the film 2 is moved in the front-back direction due to the difference in the moving distance between the film drawing mechanism C and the rear clamp mechanism D after this moving process or after the centering is completed. Pre-stretching for stretching a predetermined amount is performed, and the left and right side edges 2C of the film 2 are pressed by the movable clamp plate 20 lifted by the cylinder 18 of the left and right clamp mechanism F against the lower surface of the left and right folding plate 28 so that the film 2 and the folding plate 28 come together. It is grasped in between (states of (a) and (b) of Fig. 13). The movable clamp plate 20 is moved together with the left and right folding plates 28 in a direction to separate the film 2 in the width direction thereof by the operation of the motor 34 which starts the operation at the same timing as the end of the gripping operation or at a predetermined timing thereafter. Pre-stretching to stretch a predetermined amount is performed (Fig. 14 (a),
(State of (b)), the film 2 pulled out to the wrapping part B has its front edge 2 in a state of being pre-stretched in the front-rear, left-right direction.
The four peripheral edges of a, the rear edge 2b, and the left and right side edges 2c are held.

The carrier table H moved to the lower side of the packaging section B is pushed up toward the film 2 of the packaging section B by the vertical operation section I-2 and supplies the product 1 to the packaging section B (FIG. 6).
The two-dot chain line and the state of FIG. 16). When the top of the product 1 is raised to a predetermined height position detected by the sensor L in the process of the product 1 being pushed up by the film 2, the control means outputs the motor 34 based on the detection signal of the sensor L.
Signal is output to the motor 34 and the motor 34 is activated.
By the operation, the movable clamp plate 20 is moved together with the left and right folding plates 28 in the folding direction so as to reduce the extension amount in the width direction of the film 2 (the state of FIG. 15), and the movable clamp is moved by the air cylinder 18 at a predetermined timing. Board 20
Is released from the left and right folding plates 28, and the left and right side edges 2c of the film 2 are released (state of FIG. 17). The left and right movable clamp plate 20 separated from the lower surface of the left and right folding plate 28 is returned to the initial standby position. Then, the left and right side edges 2c of the film 2 are folded to the bottom side of the product 1 by the left and right folding plates 28 that continuously move in the folding direction (state of FIG. 18), and the left and right side edges of the film 2 are released. Approximately at the same time front and rear folding plate 23
Starts to move in the folding direction, and at the same time, the film pull-out mechanism C and the rear clamp mechanism D move in the folding direction toward each other, and the folding edges of the front and rear folding plates 23 abut each other (see FIG. ), (B) state)
When the heat sealing is completed, a series of wrapping operations for wrapping the product 1 are finished at this point. The product 1 that has been heat-sealed and packaged is stopped and waits with the gaps between the colliding edges slightly separated from each other. The operator takes it out from the front and rear folding plates 24 (state of FIG. 20) and attaches a label or the like. Is. When these series of wrapping operations are completed, the carrier table H,
The film pull-out mechanism C and the rear clamp mechanism D are returned to the initial standby position, and thereafter, the above-described operation is repeated to package the product 1.

[0020]

Since the packaging device of the present invention is constructed as described above, it has the following operational effects. ． In cooperation with the left and right folding plates, the movable clamp plates, which are placed below or in the vicinity of the left and right folding plates, are pressed against the lower surfaces of the left and right folding plates with the left and right side edges of the film pulled out to the predetermined positions of the packaging section. When the left and right folding plates move in a direction away from each other so that they can be gripped, the left and right movable clamp plates also move in synchronization with the left and right folding plates in the direction in which they separate from each other, and the film is stretched by a predetermined amount in the width direction of the film. Since it is configured to perform (pre-stretch), the number of parts of the left and right clamp mechanism, which works to grip both the left and right edges of the film and to extend it by a predetermined amount in the width direction, is smaller in number of parts than the conventional device. Since the structure is greatly simplified and simplified, and the device itself can be simplified, the manufacturing cost can be reduced and the device can be manufactured easily. Tokue achieving type of workability is improved because the lower at the same time the height of the packaging unit. ． Since the film can be pulled out to the packaging unit at a height level where the left and right folding plates are movably arranged in a direction in which they are separated from each other or approaching each other, the distance between the film pulled out to the packaging unit and the left and right folding plates is set. It can be lost. Therefore, the amount of push-up movement after the top of the package is in contact with the film is smaller than that of the conventional device, that is, the left and right side folding plates cover the left and right side edges of the film when the right and left side edges of the film are gripped by the left and right clamp mechanism. It can be kept until just before it is folded into the bottom of the package. As a result, the film can be wrapped in a beautiful and good packaging form without loosening the stretched state of the film, without causing wrinkles on the surface, and with an amount of extension of strength, and at the same time an appropriate tension can be obtained. Since it can be packaged with a stretched amount of strength, it is also effective for a so-called note ray system packaging form for packaging a plurality of (bulk) items to be packaged without using a tray. Moreover, the excess portion of the film when wrapped is reduced, and the film is not wasted.

[Brief description of drawings]

FIG. 1 is a side view showing an example of implementation of a packaging device of the present invention.

FIG. 2 is a perspective view of a main part showing a film pull-out mechanism and a rear clamp mechanism in a packaging unit.

FIG. 3 is a perspective view of a main part showing a front, rear, left and right folding mechanism in a packaging unit.

FIG. 4 is a perspective view of a main part showing a carrier and a drive mechanism thereof.

FIG. 5 is a schematic view of a state where the carrier receives the article to be packaged from the carry-in section.

FIG. 6 is a schematic view of a state in which the carrier table on which the article to be packaged is placed is moved to the lower side of the packaging section.

FIG. 7 is a schematic view of a state in which the leading edge of the film is gripped by the film drawing mechanism.

FIG. 8 is a schematic view of a state where a film having a predetermined length is pulled out.

FIG. 9 is a schematic view of a state in which the rear clamp mechanism is moved from the standby position to a position where the trailing edge of the film is gripped.

FIG. 10 is a schematic view showing a state in which the film is held by the rear clamp mechanism.

FIG. 11 is a schematic diagram of a state in which the film is separated between the film front end holding portion and the rear clamp mechanism by the film cutting mechanism.

FIG. 12 is a schematic view of a state in which the film has been transferred to a predetermined position of the packaging unit by the film drawing mechanism.

[Fig. 13] Fig. 13 is a schematic view of a state in which both widthwise edges of the film are held by the left and right folding plates and the left and right clamp plates, (a) is a plan view thereof, and (b) is a longitudinal sectional front view thereof.

[Fig. 14] Fig. 14 is a schematic view of a state in which the film is stretched (pre-stretched) by a predetermined amount in the width direction, (a) is a plan view thereof, and (b) is a longitudinal front view thereof.

FIG. 15 is a state in which the top of the article to be packaged is raised to a height detected by the sensor, and the top and bottom of the sensor detect that the left and right clamp plates move in the direction of approaching the left and right folding plates to reduce the amount of film extension. Schematic of the closed state

[Fig. 16] A schematic view of a state where the object to be packaged is lifted up and pushed up by the film of the packaging section

[FIG. 17] The left and right clamp plates are released from the lower surfaces of the left and right folding plates to release the gripping state of the left and right edges of the film.
Schematic diagram showing the folding process of the left and right edges by the left and right folding plates

[Fig. 18] A schematic view of a state in which the left and right edges of the film are folded to the bottom side of the package by the left and right folding plates.

FIG. 19 is a schematic view of a state in which the front and rear edges of the film are folded by the front and rear folding plates, (a) is a plan view thereof, and (b) is a vertical side view thereof.

[Fig. 20] Schematic view of a state in which the packaged object is taken out from the front and rear folding plates.

[Explanation of symbols]

1 ... Object to be packaged (product) 2 ... Film A ... Carrying in section B ... Packaging section C ... Film withdrawing mechanism D ... Rear clamping mechanism E ... Front / rear folding mechanism F ... Left / right clamping mechanism G ... Left / right folding mechanism 20 ... Left and right movable clamp plate 23 ... Front and back folding plate 28 ... Left and right folding plate

Claims (3)

[Claims] 1. The left and right edges of the film pulled out to a predetermined position of the wrapping section are held by the left and right clamp mechanisms, and the left and right clamp mechanisms are moved in a direction away from each other to extend and stretch the film. A stretch wrapping device in which the object to be packaged is pushed upward from below the film to cover the upper surface of the object to be packaged with the film, and then the left and right edges of the film are folded to the bottom side of the object to be packaged by the left and right folding plates. In the above, the left and right folding plates are configured to be movable in a direction of separating from or approaching each other, and can be moved toward and away from the lower surface of the left and right folding plates and move in a direction of separating or approaching the folding plates. A stretch wrapping device, wherein right and left movable clamp plates that can be synchronized with movement are arranged below or in the vicinity of the left and right folding plates. 2. The stretch wrapping device according to claim 1, wherein the left and right movable clamp plates press the lower surfaces of the left and right folding plates to grip the left and right side edges of the film. 3. The left and right movable clamp plates are synchronized with the moving direction in which the left and right folding plates move toward or away from each other while being pressed against the lower surfaces of the left and right folding plates, and when the left and right folding plates move in the approaching direction. Alternatively, the stretch wrapping device according to claim 1 or 2, wherein the stretch wrapping device is detached from the left and right folding plates and returned to the initial standby position in the movement process.